In this context, the evidence from our laboratory that erythrocytes have a critical role in body K homeostasis, along with the finding of a hereditable defect in erythrocyte K uptake in hypertensives, and 46% of their normotensive (adolescents, young adults) offspring, led us to assess whether a defective K uptake could impair the regulation of H/K exchange and oxygen delivery in CAD. Since then, a Patent Application whose filed in the USPTO,and a simple medical device for intracellular K measurement in red blood cell by miniature K and Na ion-selective electrode was proposed in conjunction with the University of Michigan.